Aluminum alloy



Patented Feb. 9, g i

UNITED STA ES PATENT OFFICE.

ALADAR IACZ, OF CLEVELAND, OHIO, ASSIGNOB, iBY MESNE ASSIGNMENTS, TO ALUMINUM COMPANY OF AMERICA, A CORPORATION OF PENNSYLVANIA.

' ALUMINUM armor.

No Drawing.

1 To all whom it may concern:

Be it known that LALADAR PACZ, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented anew and useful Aluminum Alloy, of which the following is a specification.

My invention relates to improvements 1n alloys and more particularly alloys of aluminum.

- The object of my invention is to provide an alloy which will have a close grained structure and which will therefore, have a very smooth surface when machined, and to provide an alloy possessing to a high degree the properties of resistance to warping when heated, hardness, high tensile strength and resistance to wear. More specifically, the object of my invention is to produce an aluminum alloy which may be used to advantage as a substitute for cast iron which has the disadvantage that it is heavy and can ndt be machined to present a very smooth surface.

()ne of the important uses to which my invention may be put is as a material for molds and cores for the manufacture of rubber oods. It is highly desirable to have a metal torthis purpose which will be light and therefore easy to handle and still will resist warping when heated. Moreover, it is important that'the metal be smooth so that the rubber may be stripped easily gtherefrom. The high heat conductivity which is possessed by my alloy is also advantageous in this connection as it results in the saving of time. The strength of my alloy is attested by the fact that T have made ringshaped molds therefrom which have resisted even greater compression than ordinary cast iron molds.

Another important use of my alloy is for cylinders and piston rings for automobile and other engines. The lightness and the comparatively high resistance to wear are of advantage in this connection and the fact that my alloy possesses a certain amount of elasticity is o especial importance in the use of piston rings. It has been proposed to line or cover aluminum parts with material such as iron or steel to obtain a better wearing surface than can be obtained from aluminum but still retaining the advantage of the latters low specific gravity. My alloy may be used for this purpose. and it has the Application filed September 12, 1919. Serial No. 323,850.

advantage that its co-efiicient of expansion is closer to that of aluminum than that of iron or steel.

, While attempts have been made heretofore to substitute aluminum for cast iron as a material for molds for rubber goods such as tires, the best result secured was the production of a comparatively tew tires in a single mold. By the use of my alloy, 1 have been able to produce 120 tires in a single mold without any apparent damage to the core.

Still another. use for which my invention may be applied is to articles in which the matter of ornamentation is an important consideration. My alloy possesses a very high lustre, its brilliancy being similanto that of speculum. As my alloy has a low melting point and is very fluid when melted, it is a good'material for use in die casting and in general in the manufacture of articles-in permanent molds. By varying the composition and if desired, the addition of small percentages of other metals, the color or tone may be varied to. suit various tastes.

I have produced an alloy which had a scleroscope hardness of 45 while cast iron usually runs between 28 and 4:0. This material had a tensile strength of 21,000 to 24,000 pounds per square inch which compares favorably with cast iron. The specific gravity of the alloy was less than halt of that of cast iron;

The alloys embraced by my invention contain copper and silicon. Slight amounts of other metals may be present without appreciable deleterious effect and small percent-f ages of such metals may be added to enhance certain properties which may be desirable for a particular purpose. An alloy in which such additions are incorporated would come within the scope of my invention. lit has been heretofore proposed tomakealloys of aluminum, copper and silicon but in these cases the silicon was used in a very low amount or, indeed, was present only as an impurity. I have 'found that with an aluminum content of 70 parts by weight, very good results were secured with the copper varying from 15 to 27 parts and the silicon from 2 to 15 parts. I have obtained exceptionally good results from an alloy of 67 parts aluminum, 25 parts copper and 7 parts silicon and in another case from an alloy of 72 parts aluminum, 23.5 parts copper and 4.5 silicon. Stated genery, the alloy s oul'd consist of at least 50 per cent aluminum and at least 2% percent silicon, the balance being copper. It is preferred hoyveve rgjto keep the copper below cent.

25v r v 1 produce "my alloy I may melt together the copper, aluminum' and silicon metals in any suitable manner. I may also are obtainable commercially. y Y,

- What I claim and desire to secure by Let; ters Patentof theUnited States is 1. An alloy consisting of aluminum, copperandsilicon inthe proportion substanitially of 70 constituting at least 15 and the silicon at least 2%) :per cent by weight. j

parts by weight of aluminum, to 15 to 27 parts of copper and 2 to 15 parts of silicon. a

- 2. An alloy consisting of aluminum, coper and silicon, the aluminum constituting at east450 per centby weight, the silicon constituting at least 2% per 'cent by weight and the copper constituting an appreciable percentage-by weight.

3. n alloy consisting of aluminum, ('opper and silicon, the aluminum constituting at l'east50 per cent by weight, the copper per cent by welght 

